Wednesday, August 14, 2013

Pond Starling

Canada Goose
Last month, my column was about the family life of the Canada Goose. Some of the column referred to the friendly relationship which many people have toward these geese, bordering on the pet-like. This month is the flip side on the Canada Goose.

The Canada Goose used to be the forerunner of winter and the harbinger or spring. Not anymore.

Edward Forbush in “A Natural History of American Birds,” 1925, described the reaction of people to the “flying wedge” of Canada Geese which “brings to all who see or hear the promise of another spring. The farmer stops his team to gaze; the blacksmith leaves his forge to listen as that far-carrying clamor falls upon the ear; children leave their play and eagerly point to the sky where the feathered denizens of the northern wilderness press steadily on toward the pole, babbling of the coming of spring .... Coming after the long, cold winter, not even the first call of the bluebird so stirs the blood of the listener.”

Migrating Canda Geeses

Forbush wrote when most Canada Geese still migrated to and from their breeding grounds, and when those breeding grounds were mostly north of the U.S. - Canadian border. He described it as “a distinctly American bird.”

A combination of factors has contributed to Canada Geese becoming so common and widespread that some birders now refer to them as “pond starlings,” an unflattering comparison to the European Starling which is an introduced species whose abundance, habits, and characteristics makes it a pest bordering on a pestilence.

In the case of the Canada Goose, native intelligence and adaptability has combined with human ineptitude to create a population explosion and a goose-human conflict.

Habitat loss and over-hunting caused the population of Canada Geese to hit a low point in the 1920s and 1930s. Over a period of years, a variety of steps were taken which created the situation which we have today.

Unlike many species, migration among Canada Geese is a learned trait, not an inherited trait. Some species of shore birds, for example, hatch their young, and then the adults head south. Some time later, the first year birds make their own way to the same wintering grounds to which their parents flew. Clearly, migration for these birds is encoded in their genes.

But this is not the case with Canada Geese. The geese “learn” to migrate, and when the opportunity presents itself, they “relearn” their migration. Scott Weidensaul (in “Living on the Wind”) describes how “wildlife management” effected geese migration: “Canada Geese from the central Arctic always wintered along the lower Mississippi, but in 1927 the state of Illinois converted thousands of acres of rich bottomland into a waterfowl refuge; within a few years, half of the geese on the central flyway were stopping there instead of continuing south. Then in 1941, the federal government opened the enormous Horicon National Wildlife Refuge even farther north, in Wisconsin, employing the same mix of ponds, lakes, and crops to shortstop the fickle geese that so recently had favored Illinois. The original migration to Louisiana and Arkansas, meanwhile, had dried up ....”

Simply put, with food available, the geese did not have to make the long, arduous fligh, so they did not.

Wintering Geese in southern Vermont

But the elevation of the Canada Goose to “pond starling” status really began in the 1960s and 1970s. The intent was to restore the species to the wildlife refuges and establish it in parks. Wing-clipped geese were introduced for this purpose. The effort was successful beyond all expectations, but ... the new populations of geese were non-migratory. The original wing-clipped birds couldn’t migrate; their offspring and the succeeding generations never learned to migrate, and the adaptability of the species precluded the need to migrate. In Pennsylvania, for example, there were historically no breeding Canada Geese. During the 1990s, the permanent, non-migratory population of Canada Geese in that state grew to in excess of 200,000 birds.

Again, Weidensaul: “What had started as small, picturesque flocks in widely scattered locations became larger, messier, more widespread, until by the 1990s it was hard to find a body of water without geese. The resident population in the East ... has been growing at the light-speed rate of 17 percent a year since the late 1980s ....”

Meanwhile, the number of breeding pairs in the Atlantic population in northern Quebec plummeted, causing the U.S. Fish and Wildlife Service to close Fall Canada Goose hunting in order to preserve the northern breeding population. This in turn has had economic repercussions and has disabled efforts at controlling the non-migratory goose population.

The explosion of the Canada Goose population also has a negative effect on other waterfowl species. Their size and aggressiveness drives away other nesting ducks. A beaver pond not far from my home has had no nesting Wood Ducks or Mallards. Instead, Canada Geese have laid claim to the pond.

Thirty-five years ago when the first Vermont Breeding Bird Atlas was done, the Canada Goose was present in only eight priority blocks in the entire state; nearly all of those were in the Champlain lowlands. During the second VBBA, 2003-2007, the Canada Goose was present in 136 priority blocks, a 17-fold increase. In the first atlas, Canada Goose was not present anywhere in Windham County in southeastern Vermont, not even as a possible breeding species. In the second atlas, it was present in nearly every survey block in Windham County and was one of the first species to be confirmed as breeding in most of those survey blocks.

Geese over Putney Mountain Hawk Watch, Vermont

The Putney Mountain Hawk Watch often sees the “v” formation of geese overhead, occasionally with snow geese mixed in. These are probably birds from the Canadian north who are migrating south for the winter. On the other hand, most of the several hundred Canada Geese typically counted during Christmas Bird Count in the Brattleboro area are probably non-migratory birds. They have never learned to migrate, and when the water is open and the ground is free of snow, they can find ample food.

Canada Geese, like the European Starling, are not indicators of good birding. Rather they are reminders of humanly induced environmental havoc.


  1. An interesting post. Will we ever learn? What would be the reaction to some way of culling now?